Suppose a blue car is 1/2 mile south of an intersection, driving north towards the intersection at 40 mph (miles per hour). At the same time, a red car is 1/2 mile east of the intersection, driving east (away from the intersection) at an unknown speed. The the straight-line distance between the blue and red car is increasing at a rate of 15 mph. What is the speed of the red car?

Answers

Answer 1

Answer:

dx/dt  = - 18,79 mph

Step-by-step explanation:

The two cars with the intersection point and the straight-line distance between the cars make up a right triangle. In that right triangle, the legs are the distance between each car and the intersection point, and the distance between cars is the hypothenuse

If we call  x  and  y  distances between blue car and red car respectively  and L the hypothenuse by Pythagoras theorem we have:

L²  =  x²  + y²      (1)

Tacking derivatives on both sides of the equation

2*L*dL/dt  = 2*x*dx/dt + 2*y*dy/dt

And from equation (1)

L²  = (0,5)² + (0,5)²    ⇒  L = √(0,5)²  + (0,5)²   ⇒ L = 0,5*√2

By subtitution in equation (2)

2*(0,5*√2)*15 = 2*0,5*dx/dt + 2*0,5*40

(15*√2 - 40 ) / 1  = dx/dt  [mph]

dx/dt  = - 18,79 mph

Note the( - ) sign is equivalent to say that the car is driving away from the intersection point


Related Questions

What will be the result of substituting 2 for x in both expressions below!
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Answer:

A

Step-by-step explanation:

edge

The first one is 5 and the second one is also 5

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Answer:

B) 6

Step-by-step explanation:÷

The area of a triangle = 1/2 b* h or [tex]\frac{b*h}{2}[/tex]

Line AB = 4

Line AC = 3

Line BC = x

b = 3

since it is at a right angle,

h = 4

[tex]\frac{3*4}{2}[/tex] = 6

A = 6

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base = 3
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3•4•1/2 = 6

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Answer:

47mph

Step-by-step explanation:

divide 141 by 3

Answer: 47

Work: To find the rate of speed, you divide 141 by 3, and you get 47 mph.

Helpppppppppppppppppppppppppppppppppppppp ASAP

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Answer:

is it not the plus sign? (+)

Step-by-step explanation:

I need the answers to this ASAP

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Answer:

First Answer: A = $ 4,247.03

A = P + I where

P (principal) = $ 4,000.00

I (interest) = $ 247.03

Second Answer : A = $ 6,325.22

A = P + I where

P (principal) = $ 5,500.00

I (interest) = $ 825.22

Third Answer: A = $ 7,735.55

A = P + I where

P (principal) = $ 7,000.00

I (interest) = $ 735.5

Fourth Answer: A = $ 7,735.55

A = P + I where

P (principal) = $ 7,000.00

I (interest) = $ 735.55

Step-by-step explanation:

HOPE IT HELPS MARK ME BRAINLIEST :)

I need the answer quickly

Answers

The answer will be 48/49 because you have to flip the reciprocal which is 7/8 and it turns to 8/7.

Now you change the operation to multiplication

6/7x8/7

Therefore the answer will be 48/49.

p(x)=2x3-3x2+14x÷15 and why?​

Answers

Answer:

I think you have not written the full question

Then solve each problen
Situation 1: A pair of shoes is on sale for 80% of the original price.
The sale price is $60. What was the original price?
food drive

Answers

Answer:

75

a(0.80)=60

a=60/0.80

a=75

Translate the figure 3 units left and 4 units down.
Plot all of the points of the translated figure.
You may click a plotted point to delete it.

Answers

Answer:

3,-1

Step-by-step explanation:

you go over to the left 3 and than you go down 4.

Let f(x) = 2x - 5 and g(x) = 3x. Perform the indicated
operation.

g(x)/f(x)

SOMEONE HELP PLZ

Answers

Answer:

f{3x}=6x-5

Step-by-step explanation:

There isn't really much to do: if you perform the division between function you get a new function:

[tex]h(x)=\dfrac{g(x)}{f(x)}=\dfrac{3x}{2x-5}[/tex]

1) There are about 20 million people in New York State, with a total land area of about 47,000 square miles.
What is the population density of New York State?
A. 0.0004 people per sq. mile
B. 426 people per sq. mile
C. 2,350 people per sq. mile
D. 940,000 people per sq. mile

Answers

Step-by-step explanation:

B. 426 people per square. mile

How do you write a graph that passes through the point (5, -1) and has a slope of 2 in Slope Intercept Form?

Answers

Format: y = mx + b
y = 2x + b
Plug in the point
-1 = 2(5) + b
-1 = 10 + b, b = -11
Answer: y = 2x - 11

Answer:

y=2x-11

Step-by-step explanation:

-1=2(5)+b

-1=10+b

-11=b

Complete the sentence. The x-distance between two points tells you

Answers

Answer:

distance

Step-by-step explanation:

Step-by-step explanation:

The key to finding the distance between two points is to remember that the geometric definition of subtraction is the distance between the two numbers as long as we subtract the smaller number from the larger.

The Serenity and the Mystic are sail boats. The Serenity and the Mystic start at the same point and travel away from each other in opposite directions. The Serenity travels at 16 mph and the Mystic travels at 20 mph. How far apart will they be in 2 hours? A. 52 miles B. 56 miles C. 40 miles D. 72 miles

Answers

Answer:

te puedo responder pero debes hacer primero tu tarea

Step-by-step explanation:

__% of 80 is 40 what is the =

Answers

40 / 80 = 50 so your answer would be 50%

I need help with this!!​

Answers

Answer:

14 burgers

Step-by-step explanation:

3 1/2 ÷ 1/4 = 14

Skyler has twice as many apples in her grocery bag as her
friends Macy and Janelle combined. Macy has 15 apples
in her bag. Skyler has 50 apples in her bag. How many
apples does Janelle have in her grocery bag?
The equation 2(x+15) = 50 models this situation. Which choice shows the
sequence of operations needed to solve this problem, using both arithmetic
and algebra?
WILL GIVE BRAINLIEST

Answers

Answer:

Skyler has 130 apples in her bag

Step-by-step explanation:

well first you have to add 15 and 50 and get 65 then you have to multiply 65 by two and get 130

please give brainliest

the correct answer is to

divide by 2:

2(x+15)/2 =50/2

(x+15)=25

subtract 15:

x+15-15=25-15

x=10

Can y’all please help me

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The y-intercept is 1

Mathematics, 04.03.2020 23:32 jtoole5341 DIVISION OF PROFITS Tom 20% Ellen 30% Sarah 25% Joel 25% Tom, Joel, Sarah, and Ellen divided the profits of their after-school business as shown in the circle graph above. If Tom's share of the profits was $492, what was Ellen's share?

Answers

9514 1404 393

Answer:

  $738

Step-by-step explanation:

The ratio of Ellen's share (e) to Tom's share is ...

  30%/20% = e/492

Multiplying by 492, we have ...

  e = 492(3/2) = 738

Ellen's share of the profits is $738.

The population of a town is 2100 and increasing at a rate of 1.3% per year, while the number of cats in the town is currently 1000 and increasing at a rate of 8% per year. Assuming this trend continues, estimate when the cat population will exceed the human population in this town.

Answers

Answer:

when # cats exceeds 2,313

Step-by-step explanation:

if you graph y = .013x + 2100 and y = .08 + 1000 you will see the lines intersect when the town population is 16,418 and the number of cats equals 2,313.

A typical credit card company charges 18% annual interest,
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$520 and you do not make a payment for 6 years, how much will you
owe? Answer rounded to the whole number

Answers

Answer:

$1,519

Step-by-step explanation:

Given that :

Balance = principal = $520

Time (t) = 6 years

Annual. Interest rate (r) = 18% = 0.18

Using the compound interest formula:

A = P(1 + r/n)^nt

n = number of times interest is applied per period ; A = final amount

Since interest is compounded monthly, n = 12

A = 520(1 + 0.18/12)^(12 * 6)

A = 520(1 + 0.015)^72

A = 520(1.015)^72

A = 520(2.9211579)

A = 1519.0021

Hence, final amount = $1519

Which expression is equivalent to StartFraction 1 Over sine (2 x) EndFraction minus StartFraction cosine (2 x) Over sine (2 x) EndFraction?
tan(x)
–tan(x)
StartFraction 1 Over cosine (x) EndFraction
Negative StartFraction 1 Over cosine (x) EndFraction

Answers

Answer:

Tan(x)

Step-by-step explanation:

JUST TOOK THE TEST

tan(x) is equivalent to 1/sin2x - cos2x/sin2x. Option a is correct.

To determine equivalent 1/sin2x - cos2x/sin2x.

What is tan(x)?

tan(x) is tangent of x here, tan is trigonometric operator.

Here,
= 1/sin2x - cos2x/sin2x
= (1-cos2x)/sin2x
= (2sin²x)/2sinxcosx
= sin(x)/cos(x)
= tan(x)

Thus, tan(x) is equivalent to 1/sin2x - cos2x/sin2x.

Learn more about tan(x) here:

https://brainly.com/question/15391269

#SPJ5

The ratio of boys to girls in 6th grades is 5 to 4. If there are 90 boys, how many girls would there be?

Answers

there would be 17 girls because 90 divided by 5 is 18 and then 18*4=72. please mark me brainliest

A population of 2,000 mosquitos grows at a rate of 15% per month. Which equation models the population, p(t), of the mosquitos after t months?​

Answers

A population of 2,000 mosquitos grows at a rate of 15% per month. Which equation models the population, p(t), of the mosquitos after t months?

Help me with this question ASAPPPP!!!!!!!

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answer is B , hope this helped <3

Answer:

B

Step-by-step explanation:

I think its B

Hope this helps!

Question 5(Multiple Choice Worth 4 points)
PLZZ help!
on a coordinate grid, both point (1, 2) and point (−3, −3) are reflected across the y-axis. What are the coordinates of the reflected points?

(−1, 2) and (3, −3)
(−1, −2) and (3, 3)
(1, −2) and (−3, 3)
(1, 2) and (3, 3)

Answers

Answer:

The first option (a) is correct

Step-by-step explanation:

NEED HELP!!!!!!!!!!!!!

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The answer to your question is DG.

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Eight U.S. coins are worth a total of 38 cents. How many of the coins are dimes?

Answers

Take off 3 of the pennies and the 5 that remain would be 3 nickels and 2 dimes

2 dimes=20 cents

3 nickels = 15 cents

3 pennies=3 cents

Or these 8 coins = 38 cents

20% tip of the cost of a d dollar dinner

Answers

Answer: 0.2d

Step-by-step explanation: For calculating the 20% tip of the cost in dollars of a dinner, simply multiply 0.2 by the cost of dollars of a dinner. 0.2 represents 20% and by using the variable "d" to represent the cost of the dinner, you can write this equation: 0.2d.

If y = 14 when x = 5,
find x when y = 28.

Answers

Answer:

10

Step-by-step explanation:

if its originally y=14 and x=5, if u switch y to 28 it would be 2x as much as 14 so u would multiply 5x2 aswell. hope i helped!!

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